Printing with target color data

ABSTRACT

In one embodiment, a processor-readable medium stores code representing instructions that when executed by a processor cause the processor to print a print job, and determine target color data for each sheet of the print job while printing the job. The instructions further cause the processor to continually save the target color data to a server for each sheet of the print job as each sheet is printed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is related to co-pending, co-assigned,International Patent Application No. PCT/US2011/026520, entitled,“Printing,” filed on 28 Feb. 2011, which International PatentApplication is incorporated herein in its entirety.

BACKGROUND

Color output in printing systems can be affected by print componentswhose conditions change during the lifetime and usage of the printingsystem. For example, component temperatures, sheet material properties,electrical resistances, ink properties, toner properties such asconductivities and densities, binary ink developer properties, and/orother states may change during the lifetime and usage of a printer. Mostprinters are calibrated on a regular basis (e.g., after having printed acertain number of sheets) to maintain better control of the coloroutput. For example, some digital presses run a full color calibrationapproximately every 10,000 or 20,000 printed sheets to improve thealignment of the digital input with the color output. However, theability to consistently reproduce colors across printing presses remainsa generally unresolved aspect of digital commercial presses.

BRIEF DESCRIPTION OF THE DRAWINGS

The present embodiments will now be described, by way of example, withreference to the accompanying drawings, in which:

FIG. 1 shows an exemplary printing environment suitable for implementingcontinuous inter-press color matching as disclosed herein, according toan embodiment;

FIG. 2 shows an exemplary printing system implemented as a printingpress, according to an embodiment;

FIG. 3 shows an exemplary server, according to an embodiment;

FIGS. 4, 5 and 6, show flowcharts of example methods related to printingwith target color data, according to embodiments.

DETAILED DESCRIPTION

Overview

As generally noted above, the ability to consistently reproduce colorsacross printing presses is an important, but generally unresolved,aspect of digital commercial presses. In addition to the generalimportance of maintaining consistent color reproduction in digitalpresses, such consistency has even greater consequences when usingcertain customer printing modes. For example, digital presses areincreasingly being used for printing photo albums, and the same printjobs are now often being printed on multiple, different presses.

When printing photo albums, the print jobs are usually short, but theydemand superb color consistency between front and back pages. Inaddition, photo albums are commonly printed on two-engine web presses.Because photo albums often have photos that are big enough to occupy twoconsecutive pages within the album, it is a common occurrence to havehalf of a photo image printed by one print engine while the other halfof the image is printed by another print engine. Therefore, in a photoalbum printing mode, if the two print engines do not reproduce colorswith a high degree of uniformity, the color discrepancies from page topage within the album will be very apparent, and customers may rejectthe photo album.

Inconsistency in color reproduction between printing presses is alsobecoming more noticeable as more printing press customers are beginningto use multiple presses to print a single print job (i.e., the sameprint job printed across multiple presses). Multiple presses, located atthe same printing site or at multiple printing sites, are increasinglybeing used to print the same print job. The use of multiple presses toprint the same job provides a customer with a direct and easy comparisonof the color output produced on the different presses. Therefore,printing a single job on multiple presses is another print mode thattends to make inconsistent color reproduction between presses veryapparent to customers.

Currently, there are few if any solutions for providing consistent colorreproduction across two or more printing presses (or print engines). Onemethod of calibrating different presses is to perform a precise colorcalibration using the same calibration page between the differentpresses. In another method, a device correction link can be providedbetween the different presses. While such methods may offer a limitedmeasure of color calibration at the start of a print job, there has notbeen a solution that provides consistent color reproduction across twoor more printing presses that continually calibrates the presses as ajob is being printed.

Embodiments of the present disclosure, however, provide continuousinter-press color matching that enables different printing presses toconverge to the same color values for each page or sheet of a print job.A server database stores data for two or more relevant printing presses.Among the two or more presses, and at any given time, a particular presscan be a “master” press that automatically and continuously saves targetcolor data to a server database as it prints a job. The data includes,or is labeled with, identifiers that uniquely identify the print jobbeing printed, each sheet or page of the print job, and the printingpress that serves as the master press for the identified print job.Also, among the two or more printing presses, a “slave” press can accessthe server and read the master press target color data by identifyingthe print job. The slave press can then print the identified print jobusing the same target color data used by the master press. The terms“master” and “slave” as used herein with reference to different printingpresses are merely intended to provide a descriptive indication,respectively, of a first press that initially prints a print job andsaves target color data, and a second press that uses the saved targetcolor data to follow the color output of the first press.

The server acts as a cloud server, containing and transferring thetarget color data between master and slave printing presses. Thisenables a slave press to match the master press target color data on aprint job while printing the job at virtually the same time as themaster press, or while printing the job at some later time after themaster press has completed the print job. At least a minimal time delayis called for between printing on the master press and the slave pressto enable the slave press to access the correct color data for eachsheet of the job and to match the data with the appropriate sheetprinted on the slave press.

In one example embodiment, a processor-readable medium stores coderepresenting instructions that when executed by a processor cause theprocessor to print a print job and determine target color data for eachsheet of the print job while printing the job. The instructions furthercause the processor to continually save the target color data for eachsheet to a server as each sheet is being printed.

In another example embodiment, a processor-readable medium stores coderepresenting instructions that when executed by a processor cause theprocessor to initiate a print job on a slave press, and request targetcolor data for the print job from a server. The instructions furthercause the processor to receive target color data for each sheet of theprint job as the target color data for each sheet is saved to the serverfrom a master press. The instructions then cause the processor tocontrol the slave press so that it prints each sheet of the print jobaccording to the target color data.

In another example embodiment, a processor-readable medium stores coderepresenting instructions that when executed by a processor cause theprocessor to receive from a first printing press, target color data foreach sheet of a print job as each sheet is printed on the first press.The instructions further cause the processor to identify and save thetarget color data in a memory of a server according to a first pressidentifier, a print job identifier, and individual sheet identifiersthat identify each sheet. The instructions further cause the processorto receive a request for the target color data from a second press assheets are printed on the first press. The request includes the printjob identifier to identify the print job. The instructions then causethe processor to, in response to the request, send target color data foreach sheet of the print job to the second press on a sheet-by-sheetbasis as the target color data for each sheet is received from the firstpress and saved in the memory of the server.

In another example embodiment, a printing system includes a processorand target color data stored in a memory. The target color data includesolids and gray level target data for each sheet of a print job beingprinted on the printing system. The system further includes a continuousinter-press color match module stored in the memory and executable onthe processor to continually upload the target color data on asheet-by-sheet basis to a server as the target color data is beingdetermined by the processor.

Illustrative Embodiments

FIG. 1 shows an exemplary printing environment 100 suitable forimplementing continuous inter-press color matching as disclosed herein,according to an embodiment of the disclosure. Printing environment 100includes two or more printing systems 102 (e.g., printing presses 102a-102 n) coupled to one another through a server 104 via a network 106.Network 106 is intended to represent any of a variety of conventionalnetwork topologies and types (including optical, wired and/or wirelessnetworks), employing any of a variety of conventional network protocols(including public and/or proprietary protocols). Network 106 mayinclude, for example, a corporate network, a home network, or theInternet, as well as one or more local area networks (LANs) and/or widearea networks (WANs), and combinations thereof.

A printing system 102 may be any type of printer or press, such as anytype of offset printer or press. In the embodiment shown in FIG. 1,printing systems 102 each comprise a digital press 102, such as a liquidor dry electrophotographic digital press 102. FIG. 2 shows an exemplaryprinting system 102 implemented as a printing press 102, according to anembodiment of the disclosure. Each press 102 is generally configured toprint a variety of characters, symbols, graphics, images and the like,onto media sheets 200. Sheets 200 can comprise a variety of suitablemedia types such as paper, card stock, transparencies, Mylar, and thelike.

Press 102 includes an image transfer arrangement 202. In someimplementations, the image transfer arrangement 202 includes a developerdrum 204 and an image transfer drum 206 for imprinting liquid toner ontomedia sheets 200. In other implementations, the image transferarrangement 202 comprises dry toner drums, offset printing drums or aprint head. Press 102 also includes an image sensor 208, arranged tomeasure color outputs 210 printed on media sheets 200.

Press 102 includes one or more processors 212 andprocessor/computer-readable memory components 214 (e.g., volatile andnon-volatile memory components) that store processor/computer-executableinstructions in the form of various firmware, software, applications,modules, and so on. Memory 214 also stores various types of data anddata structures, such as documents and/or files to be printed ontosheets 200. Such data can form print jobs that include print jobcommands and/or command parameters, for example. In general, processor212 executes instructions from memory 214 to control components of press102 such as the image transfer arrangement 202 and image sensor 208during normal operation of the press 102.

In one implementation, memory 214 includes a continuous colorcalibration (CCC) module 216. The CCC module 216 includes instructionsthat when executed on processor 212, cause the processor 212 to performa CCC algorithm 216 that keeps color consistency of both solids and graylevels. The CCC algorithm 216 enables a press 102 to consistently printthe same colors throughout a long print job, by measuring target colordata values 218 for each sheet of the print job at the beginning of theprinting, and by adjusting developer voltages and grays look-up-tables(LUTs) accordingly in consecutive spreads in order to overcome colorvariations from sheet to sheet. The CCC algorithm is discussed in detailin the co-pending, co-assigned, International Patent Application No.PCT/US2011/026520, entitled, “Printing,” filed on 28 Feb. 2011, which isincorporated herein in its entirety.

In one embodiment, the CCC algorithm 216 includes printing first coloroutputs on media sheets 200 using pre-calibrated color values obtainedduring a regular full color calibration. The first color outputs arethen measured with the image sensor 208, and target color data values218 are then determined, or based upon the first color outputs. Thetarget color data values 218 are stored in a memory 214, and they maycomprise a target LUT that couples a number of digital inputs to thecorresponding first color outputs. Current color outputs are thenprinted on sheets 200 and measured. In time, due to changes in certainprint component states (e.g., temperatures, toner conductivity, tonerdensity, substrate color or material, certain material properties, inkproperties, toner properties, binary ink developer properties), currentcolor values being printed may differ from the target color values 218.Color compensation values are then calculated to compensate for adifference between the target color values 218 and the current colorvalues. As printing continues, the color compensation values are used tocouple more correct digital input with desired color output to betterachieve the target color values 218.

Referring again to FIG. 2, in one implementation, memory 214additionally includes a continuous inter-press color match (CIPCM)module 220. The CICPM module 220 includes instructions that whenexecuted on processor 212, cause the processor 212 to perform a CICPMalgorithm 216 that enables continuous color matching of both solids andgray levels between two or more printing presses 102.

In one implementation, the CICPM algorithm 220 operates to cause a press102 to act as a “master” press with respect to a particular print jobcurrently being printed. For example, while press #1, 102 a (FIG. 1),prints a print job #1, press #1 operates as a master press with respectto print job #1. While the press 102 is printing the print job, theCICPM algorithm 220 operates to continuously upload target color datavalues 218 (i.e., the solids and gray levels) to a server 104. Targetcolor data values 218 are determined by the CCC algorithm 216 for eachsheet of a print job as the press 102 prints the job. The CICPMalgorithm 220 causes processor 212 to upload the target color datavalues 218 to the server 104, on a sheet-by-sheet basis, as each sheetis being printed. In one implementation, while saving the target colordata 218 to the server 104, the CICPM algorithm 220 also causes theprocessor 212 to provide identification information to the server 104.The identification information can include a job identifier thatidentifies the particular job being printed (e.g., job #1), a pressidentifier that identifies the particular press that is printing the job(e.g., press #1), and a sheet identifier that identifies the particularsheet (e.g., sheet #1) within the job with which particular target colordata is associated. As discussed below, in another implementation, theCICPM algorithm 220 operates to cause a press 102 to act as a “slave”press with respect to a particular print job.

FIG. 3, shows an exemplary server 104, according to an embodiment of thedisclosure. Server 104 is intended to represent any of a variety of webservers capable of manipulating data and other content and delivering itover a network 106, such as the Internet, to devices such as printingpresses 102, or other computing devices. Server 104 can be a remoteserver accessible over a remote network connection, or a local serveraccessible over a local network connection. Server 104 may beimplemented as any of a variety of conventional computing devicesconfigurable to communicate with presses 102, including, for example, aworkstation, a desktop PC, a tablet PC or other portable computer, awireless communications device, combinations thereof, and so on. Server104 generally includes a processor (CPU) 300, a memory 302 (e.g.,volatile and non-volatile memory components). Memory 302 comprisesprocessor/computer-readable media that provides for the storage ofprocessor/computer-executable instructions in the form of variousfirmware, software, applications, modules, and so on. Memory 302 alsostores various types of data and data structures, such as target colordata 218 from one or more presses 102. In one implementation, suchtarget color data 218 is stored in a target color data collection 306. Atarget color data collection 306 can include target color data 218 froma number of different printing presses 102. Server 104 also typicallyincludes various input/output devices 318 such as a keyboard, a mouse,and a monitor.

Server 104 may implement various application programs and/or otherinstructions stored in memory 302 that are executable on processor 300to enable transactions with a number of presses 102 via a network 106,through the input, manipulation, and/or other preparation of data inelectronic form (e.g., through data transfer, text entry, mouse clicks,etc.). In one implementation, for example, processor 300 on server 104executes instructions from a target color data transfer module 308 toreceive, organize, save, and transmit target color data between printingpresses 102.

In one example, as a first or “master” press 102 a (e.g., press #1, 102a) prints a print job, the press #1, 102 a, continually uploads targetcolor data 218 a to the server 104. The target color data 218 a for eachsheet of the job is uploaded as each sheet of the job is being printedon the first/master press #1. Accordingly, instructions in data transfermodule 308 execute on a processor 300 to receive target color data foreach sheet of the print job as each sheet is printed by the first/masterpress #1, 102 a. The transfer module 308 further executes to identifyand save the target color data 218 a in memory 302 of server 104according to identification information received from the first/masterpress #1, 102 a. The identification information can include a jobidentifier that identifies the particular job being printed (e.g., job#1), a press identifier that identifies the particular press printingthe job (e.g., press #1), and a sheet identifier that identifies theparticular sheet (e.g., sheet #1) within the job with which particulartarget color data 218 a is associated.

When saving the target color data 218 a to memory 302, in oneimplementation the data transfer module 308 executes on a processor 300to organize the target color data 218 a within a target color datacollection 306. For example, target color data 218 a can be organizedinto a target color data collection 306 as shown below in Table 1.Tables 1-4 show one example organization of target color data 218 a-218Nfrom numerous presses #1-#N (e.g., presses 102 a-102N), as it mightappear within a target color data collection 306 on server 104. It isnoted that the organization of data shown in Tables 1-4 is purely forillustrative purposes, and that the actual organization of target colordata on server 104 would likely take on a different format. In addition,the data values shown below in Tables 1-4 are arbitrary, and they arenot intended to provide any indication as to the actual Solids and Graylevels data values that may be present in a target color data collection306 on server 104.

TABLE 1 Target Color Data 218a Press #1 Job #1 Sheet 1 Sheet 2 Sheet NSolids 15 35 75 Grays 50 75 80

TABLE 2 Target Color Data 218b Press #2 Job #2 Sheet 1 Sheet 2 Sheet NSolids 25 35 50 Grays 80 60 65

TABLE 3 Target Color Data 218c Press #3 Job #3 Sheet 1 Sheet 2 Sheet NSolids 65 40 90 Grays 75 75 70

TABLE 4 Target Color Data 218n Press #N Job #N Sheet 1 Sheet 2 Sheet NSolids 85 15 55 Grays 90 85 25

Referring again to server 104 of FIG. 3, as a print job (e.g., job #1)is being printed on a first/master press 102 a (e.g., press #1), and thetarget color data transfer module 308 executes on a processor 300 toreceive and save target color data 218 a for each sheet of the job #1into the server memory 302, in one implementation, the transfer module308 further executes to receive a request from a second or “slave” press102 b (e.g., press #2). The request from a second/slave press #2, 102 b,includes identification information that at least identifies a print jobfor which the second/slave press #2 is requesting to receive targetcolor data 218. For example, the request from the second/slave press #2may include job identification information identifying job #1. Therequest may also include additional identification information thatidentifies the press that printed or is printing job #1, as well asspecific sheet identification information that identifies a particularsheet number. In response to the request from the second/slave press #2,102 b, the data transfer module 308 executes to send the identifiedtarget color data 218 a for each sheet of the print job #1 to thesecond/slave press #2 on a continual basis. The data is sent to thesecond/slave press #2 on a sheet-by-sheet basis as the target color datafor each sheet is received from the first/master press #1 and saved inthe memory 302 of server 104.

Thus, the server 104 receives, organizes, saves and transfers targetcolor data 218 between “master” and “slave” printing presses, enabling aslave press to match the master press target color data on a given printjob. Because a master press continually saves target color data toserver 104 on a sheet-by-sheet basis, a slave press can print the samejob as the master press at almost the same time, with there being only aslight time delay between printing on the master and slave presses. Aminimal time delay between printing on the master press and the slavepress enables the slave press to access the correct color data for eachsheet of the job and to match the data with the appropriate sheet beingprinted on the slave press. In another implementation, a slave press canaccess target color data from server 104 after the master press hasalready completed printing the print job and saved all of the targetcolor data to the server. Thus, the target color data 218 remains on theserver 104 and is accessible at any future time by any printing press102, including the master press that initially saved the target colordata to the server 104.

Referring again to FIG. 2, as noted above, in one implementation theCICPM algorithm 220 executes on a press 102 to cause a press 102 to actas a “slave” press with respect to a particular print job. For example,while press #1, 102 a (FIG. 1), prints a print job #1, press #1 operatesas a master press with respect to print job #1 and saves target colordata 218 a to server 104. At the same time, or at some time in thefuture, press #2, 102 b (FIG. 1), can be printing the same print job #1.In this case, the CICPM algorithm 220 executes on press #2 to make arequest to the server 104 to retrieve the target color data 218 a sothat it can use the target color data 218 a to match its own coloroutputs with those of press #1 when press #1 printed the print job #1.In this respect, the CICPM algorithm 220 causes press #2, 102 b, to actas a “slave” press, following the color outputs of the “master” press.

In one implementation, the same press can act as both the master pressand the slave press. For example, press #1 can initially operate as amaster press with respect to print job #1, as it saves target color data218 a to server 104. At some time in the future, if print job #1 is tobe printed again on press #1, press #1 can then operate as a slave presswith respect to print job #1. In this case, press #1 sends a request tothe server 104 to retrieve the previously saved target color data 218 ain order to follow the same color outputs that it initially achievedwhen it printed print job #1 the first time.

In general, when a press 102 acts as a slave press, the CICPM algorithm220 executes on the press 102 to make a request to the server 104 toretrieve target color data 218 for a particular print job. The requestincludes identification information that at least identifies a print jobfor which the slave press 102 is requesting to receive target color data218. For example, the request from a slave press 102 may include jobidentification information identifying a print job #1. The request mayalso include additional identification information that identifies thepress that printed, or is printing job #1, as well as specific sheetidentification information that identifies a particular sheet number.The slave press 102 can receive target color data for each sheet of theprint job #1 as while, or shortly after, the target color data for eachsheet is being saved to the server 104 from a master press. In oneimplementation, where the target color data for all sheets of the printjob #1 have already been previously saved to the server 104 by themaster press, the target color data for the entire print job is receivedby the slave press. Upon receiving the target color data 218, theprocessor controls the slave press to print each sheet of the print jobaccording to the target color data.

In different implementations, the CICPM algorithm 220 can execute on aslave press 102 in an absolute target color mode and a relative targetcolor mode. As noted above, each press 102 executes a CCC algorithm 216that determines target color data for a print job. However, in theabsolute target color mode, when the slave press receives master targetcolor data 218 from server 104, it overrides its own target color datawith the master target color data to print the job. In the relativetarget color mode, the slave press receives master target color datafrom the server 104 that comprises target color deltas from its owntarget color data. In this mode, the slave press does not override itsown target color data, but instead it calculates corrections using thedeltas received from the server 104.

FIGS. 4, 5 and 6, show flowcharts of example methods 400, 500 and 600,related to printing with target color data, according to embodiments ofthe disclosure. Methods 400, 500 and 600 are associated with theembodiments discussed above with regard to FIGS. 1-3, and details of thesteps shown in methods 400, 500 and 600, can be found in the relateddiscussion of such embodiments. The steps of methods 400, 500 and 600,may be embodied as programming instructions stored on acomputer/processor-readable medium, such as memory 214 and 302 of FIGS.2 and 3. In an embodiment, the implementation of the steps of methods400, 500 and 600, is achieved by the reading and execution of suchprogramming instructions by a processor, such as processor 212 and 300of FIGS. 2 and 3. Methods 400, 500 and 600, may include more than oneimplementation, and different implementations of methods 400, 500 and600, may not employ every step presented in the respective flowcharts.Therefore, while steps of methods 400, 500 and 600, are presented in aparticular order within their respective flowcharts, the order of theirpresentation is not intended to be a limitation as to the order in whichthe steps may actually be implemented, or as to whether all of the stepsmay be implemented. For example, one implementation of method 400 mightbe achieved through the performance of a number of initial steps,without performing one or more subsequent steps, while anotherimplementation of method 400 might be achieved through the performanceof all of the steps.

Method 400 of FIG. 4, begins at block 402, where the first step shown isto print a print job. At block 404, the method 400 continues withdetermining target color data for each sheet of the print job while thejob is printing. In one embodiment, as discussed above, target colordata is determined by a CCC algorithm that executes to print first coloroutputs on media sheets using pre-calibrated color values obtainedduring a regular full color calibration. The first color outputs arethen measured with an image sensor 208, and target color data values 218are then determined, or based upon the first color outputs.

The method 400 continues at block 406 with continually saving the targetcolor data to a server for each sheet as each sheet of the job isprinted. The server can be a remote server accessible over a remotenetwork connection, a local server accessible over a local networkconnection, or a server in another configuration. At block 408 of method400, identification information is provided to the server when thetarget color data is being saved to the server. The identificationinformation can include a job identifier to identify the print job, apress identifier to identify a printing press that is printing the printjob, and a sheet identifier for each sheet to associate target colordata with each sheet.

As shown at block 410, after all of the target color data for the printjob is saved to the server, the method 400 continues at block 412 withrequesting the target color data back from the server and identifyingthe print job in the request by the job identifier. In thisimplementation, the same press that previously acted as a master pressto save the target color data to the server, is now acting as a slavepress to retrieve the target color data back from the server, as shownat block 414. At block 416, the printing press is controlled to printthe print job a second time using the target color data associated witheach sheet.

Method 500 of FIG. 5, begins at block 502, where the first step shown isto initiate a print job on a slave press. At block 504, target colordata for the print job is requested from a server. The request includessending a print job identifier to the server. At block 506, method 500continues with receiving target color data for each sheet of the printjob as the target color data for each sheet is being saved to the serverfrom a master press. The receiving can also include, in an embodiment,receiving target color data for the entire print job, where the targetcolor data for all sheets of the print job has been previously saved tothe server by the master press. The server can be a remote serveraccessible over a remote network connection, or a local serveraccessible over a local network connection. At block 508 of method 500,the slave press is then controlled in order to print each sheet of theprint job according to the target color data.

Method 600 of FIG. 6, begins at block 602, where the first step shown isto receive from a first printing press, target color data for each sheetof a print job as each sheet is being printed on the first press. Atblock 604, the target color data is identified and saved in a memory ofa server according to a first press identifier, a print job identifier,and sheet identifiers. At block 606 of method 600, as sheets are printedon the first press, a request for the target color data is received froma second press. The request from the second press includes the print jobidentifier. At block 608 of method 600, in response to the request,target color data for each sheet of the print job is sent to the secondpress on a sheet-by-sheet basis as the target color data for each sheetis saved in the memory of the server. In one implementation, the targetcolor data for the entire print job is sent, where the target color datafor all sheets of the print job has been previously saved to the memoryof the server by the first press. As shown at block 610 of method 600,the first press and the second press can be the same press.

What is claimed is:
 1. A non-transitory processor-readable medium storing code representing instructions that when executed by a processor cause the processor to: determine, by a first printer printing a print job, target color data for each sheet of the print job while printing; and continually save, by the first printer, the target color data to a server for each sheet as each sheet is printed, wherein each sheet is a sheet in a plurality of sheets, wherein the continually saved target color data is retrieved by a second printer to print a portion of the print job simultaneously with the printing by the first printer.
 2. A non-transitory processor-readable medium as in claim 1, wherein the instructions further cause the processor to: when saving the target color data to the server, provide to the server, a job identifier to identify the print job, an identifier to identify the first printer that is printing the print job, and a sheet identifier for each sheet to associate target color data with each sheet.
 3. A non-transitory processor-readable medium as in claim 1, wherein the instructions further cause the processor to: after all of the target color data for the print job is saved, request the target color data from the server and identify the print job in the request by the job identifier; receive the target color data from the server; and control the first printer to print the print job a second time using the target color data associated with each sheet, or control a second printer to print the print job a second time using the target color data associated with each sheet.
 4. A non-transitory processor-readable medium as in claim 1, wherein continually saving the target color data to a server comprises saving the target color data to a server selected from the group consisting of a remote server accessible over a remote network connection, and a local server accessible over a local network connection.
 5. A non-transitory processor-readable medium as in claim 1, wherein determining target color data for each sheet of the print job while printing comprises: determining pre-calibrated color values in a full color calibration; printing first color outputs on media sheets using the pre-calibrated color values; and measuring the first color outputs with an image sensor and determining the target color data based on the measured first color outputs.
 6. A non-transitory processor-readable medium as in claim 1, wherein each sheet in the plurality of sheets includes at least a slight color variation. 